Buggy code:
private void formatLocalDeclaration ( LocalDeclaration localDeclaration , BlockScope scope , boolean insertSpaceBeforeComma , boolean insertSpaceAfterComma ) { } private void formatMessageSend ( MessageSend messageSend , BlockScope scope , Alignment messageAlignment ) { } private void formatMethodArguments ( AbstractMethodDeclaration methodDeclaration , boolean spaceBeforeOpenParen , boolean spaceBetweenEmptyParameters , boolean spaceBeforeClosingParen , boolean spaceBeforeFirstParameter , boolean spaceBeforeComma , boolean spaceAfterComma , int methodDeclarationParametersAlignment ) { } private void formatEnumConstantArguments ( FieldDeclaration enumConstant , boolean spaceBeforeOpenParen , boolean spaceBetweenEmptyParameters , boolean spaceBeforeClosingParen , boolean spaceBeforeFirstParameter , boolean spaceBeforeComma , boolean spaceAfterComma , int methodDeclarationParametersAlignment ) { } private void formatNecessaryEmptyStatement ( ) { } private void formatOpeningBrace ( String bracePosition , boolean insertSpaceBeforeBrace ) { } private void formatStatements ( BlockScope scope , final Statement [ ] statements , boolean insertNewLineAfterLastStatement ) { } private void formatThrowsClause ( AbstractMethodDeclaration methodDeclaration , boolean spaceBeforeComma , boolean spaceAfterComma , int alignmentForThrowsClause ) { } private void formatTypeMembers ( TypeDeclaration typeDeclaration ) { } private void formatTypeOpeningBraceForEnumConstant ( String bracePosition , boolean insertSpaceBeforeBrace , TypeDeclaration typeDeclaration ) { } private void formatTypeOpeningBrace ( String bracePosition , boolean insertSpaceBeforeBrace , TypeDeclaration typeDeclaration ) { } private int getDimensions ( ) { } private boolean hasComments ( ) { } private boolean isNextToken ( int tokenName ) { } private boolean isClosingGenericToken ( ) { } private boolean isGuardClause ( Block block ) { } private boolean isMultipleLocalDeclaration ( LocalDeclaration localDeclaration ) { } private boolean isPartOfMultipleLocalDeclaration ( ) { } private void manageClosingParenthesizedExpression ( Expression expression , int numberOfParens ) { } private void manageOpeningParenthesizedExpression ( Expression expression , int numberOfParens ) { } public boolean visit ( AllocationExpression allocationExpression , BlockScope scope ) { } public boolean visit ( AND_AND_Expression and_and_Expression , BlockScope scope ) { } public boolean visit ( AnnotationMethodDeclaration annotationTypeMemberDeclaration , ClassScope scope ) { } public boolean visit ( Argument argument , BlockScope scope ) { } public boolean visit ( ArrayAllocationExpression arrayAllocationExpression , BlockScope scope ) { } public boolean visit ( ArrayInitializer arrayInitializer , BlockScope scope ) { } public boolean visit ( ArrayQualifiedTypeReference arrayQualifiedTypeReference , BlockScope scope ) { } public boolean visit ( ArrayQualifiedTypeReference arrayQualifiedTypeReference , ClassScope scope ) { } public boolean visit ( ArrayReference arrayReference , BlockScope scope ) { } public boolean visit ( ArrayTypeReference arrayTypeReference , BlockScope scope ) { } public boolean visit ( ArrayTypeReference arrayTypeReference , ClassScope scope ) { } public boolean visit ( AssertStatement assertStatement , BlockScope scope ) { } public boolean visit ( Assignment assignment , BlockScope scope ) { } public boolean visit ( BinaryExpression binaryExpression , BlockScope scope ) { } public boolean visit ( Block block , BlockScope scope ) { } public boolean visit ( BreakStatement breakStatement , BlockScope scope ) { } public boolean visit ( CaseStatement caseStatement , BlockScope scope ) { } public boolean visit ( CastExpression castExpression , BlockScope scope ) { } public boolean visit ( CharLiteral charLiteral , BlockScope scope ) { } public boolean visit ( ClassLiteralAccess classLiteral , BlockScope scope ) { } public boolean visit ( Clinit clinit , ClassScope scope ) { } public boolean visit ( CompilationUnitDeclaration compilationUnitDeclaration , CompilationUnitScope scope ) { } public boolean visit ( CompoundAssignment compoundAssignment , BlockScope scope ) { } public boolean visit ( ConditionalExpression conditionalExpression , BlockScope scope ) { } public boolean visit ( ConstructorDeclaration constructorDeclaration , ClassScope scope ) { } public boolean visit ( ContinueStatement continueStatement , BlockScope scope ) { } public boolean visit ( DoStatement doStatement , BlockScope scope ) { } public boolean visit ( DoubleLiteral doubleLiteral , BlockScope scope ) { } public boolean visit ( EmptyStatement statement , BlockScope scope ) { } public boolean visit ( FieldDeclaration enumConstant , MethodScope scope ) { this . scribe . printComment ( ) ; final int line = this . scribe . line ; this . scribe . printModifiers ( enumConstant . annotations , this ) ; <START_BUG> this . scribe . printNextToken ( TerminalTokens . TokenNameIdentifier , true ) ; <END_BUG> formatEnumConstantArguments ( enumConstant , this . preferences . insert_space_before_opening_paren_in_enum_constant , this . preferences . insert_space_between_empty_parens_in_enum_constant , this . preferences . insert_space_before_closing_paren_in_enum_constant , this . preferences . insert_space_after_opening_paren_in_enum_constant , this . preferences . insert_space_before_comma_in_enum_constant_arguments , this . preferences . insert_space_after_comma_in_enum_constant_arguments , this . preferences . alignment_for_arguments_in_enum_constant ) ; Expression initialization = enumConstant . initialization ; if ( initialization instanceof QualifiedAllocationExpression ) { TypeDeclaration typeDeclaration = ( ( QualifiedAllocationExpression ) ( initialization ) ) . anonymousType ; int fieldsCount = ( ( typeDeclaration . fields ) == null ) ? 0 : typeDeclaration . fields . length ; int methodsCount = ( ( typeDeclaration . methods ) == null ) ? 0 : typeDeclaration . methods . length ; int membersCount = ( ( typeDeclaration . memberTypes ) == null ) ? 0 : typeDeclaration . memberTypes . length ; String enum_constant_brace = this . preferences . brace_position_for_enum_constant ; formatLeftCurlyBrace ( line , enum_constant_brace ) ; formatTypeOpeningBraceForEnumConstant ( enum_constant_brace , this . preferences . insert_space_before_opening_brace_in_enum_constant , typeDeclaration ) ; if ( this . preferences . indent_body_declarations_compare_to_enum_constant_header ) { this . scribe . indent ( ) ; } if ( ( ( fieldsCount != 0 ) || ( methodsCount != 0 ) ) || ( membersCount != 0 ) ) { formatTypeMembers ( typeDeclaration ) ; } this . scribe . printComment ( ) ; if ( this . preferences . indent_body_declarations_compare_to_enum_constant_header ) { this . scribe . unIndent ( ) ; } if ( this . preferences . insert_new_line_in_empty_enum_constant ) { this . scribe . printNewLine ( ) ; } this . scribe . printNextToken ( TerminalTokens . TokenNameRBRACE ) ; this . scribe . printTrailingComment ( ) ; if ( enum_constant_brace . equals ( DefaultCodeFormatterConstants . NEXT_LINE_SHIFTED ) ) { this . scribe . unIndent ( ) ; } if ( hasComments ( ) ) { this . scribe . printNewLine ( ) ; } } return false ;

Fix:
this . scribe . printNextToken ( TerminalTokens . TokenNameIdentifier , false ) ;